1. Field of the Invention
This invention generally pertains to ureido-terminated compounds and more particularly to ureido-terminated polyoxyalkylene compounds and their method of preparation.
2. Prior Art
Ureido-terminated compounds are generally well known in the art. These compounds have many well known uses. Among the most widely known is the polymeric condensation with an aldehyde to form urea-aldehyde resins.
Aliphatic or aromatic, compounds having a single terminal ureido group are well known. It has been disclosed in U.S. Pat. No. 2,145,242 to Arnold that diureido terminated alihatic compounds can be produced by reacting an aliphatic diamine wherein each terminal amine has at least one labile hydrogen with urea.
Additionally, polyalkylenepolyamine-containing compounds having primary or secondary amine termination are shown to form ureido containing compounds. For example, triethylenetetramine can be reacted with urea at temperatures of 120.degree. C. to 160.degree. C. to form thermoplastic resinous polymers soluble in alcohols, ketones, and esters but insoluble in hydrocarbons and only limitedly soluble in water.
Further, it has been disclosed that aliphatic primary diamines and particularly those wherein the amine groups are separated by alkylene hydrocarbons yield crystalline monomeric compounds when reacted with urea. These compounds have a relatively high melting point, i.e., 180.degree. C.-190.degree. C. and are relatively insoluble in even boiling alcohol. Additionally, Arnold discloses that mono oxycontaining amines yield ureas which are similar in characteristic.
It has now been discovered that a certain class of polyether primary amine terminated compounds form polyether containing polyureides. These compounds unexpectedly form homogeneous solutions with aqueous formaldehyde and solvents. Additionally, the compounds of the instant invention reduce the punking of phenolic foams while simultaneously forming a portion of the polymer.